Semiletov and Shakhova were not 'hinting' at anything. They were telling you point blank.
The area of hotspots of methane are spreading, now encompassing a full 10% of the 2 million sq km of the ESAS. Which is 200,000 sq km.
Not only is the area of release spreading, the rate and volume of release is increasing, and they expect it to increase exponentially 3-5 orders of magnitude.
That there is no way to shut this off, short of sea level dropping and exposing the shelves to temperatures capable of refreezing the permafrost. We know that isn't going to happen.
That the methane will continue to release until there is no more to release, and that just 1% of the available methane will be enough to cause catastrophic climate change.
The interview with Semiletov and Shakhova was published 24 June 2017. their paper, http://www.nature.com/articles/ncomms15872 Current rates and mechanisms of subsea permafrost degradation in the East Siberian Arctic Shelf, was published 22 June 2017.